Transient analysis of scattering from impedance surfaces using physical optics approximation

Abstract

Analysis of transient scattering from impedance surfaces using physical optics (PO) approximation is presented. Specifically, a fast relaxed vector fitting scheme is applied to determine a weighted rational function fit to the surface impedance and associated functions in the frequency domain, then inverse Fourier transformed to the time domain in terms of decaying exponential functions. The scattered fields are obtained by convolving the time-dependent surface impedance (and associated functions) and the PO integral, which is determined via closed-form expressions obtained using the Radon transform interpretation. The numerical examples that demonstrate the applicability and validity of the proposed method are shown.